Lamp-socket.



No.. 727,590. I PATBNTED MAY 12, 1903. l W. H. COLE.

LAMP SOCKET.

APPLICATION FILED AUG. 19. 1902.

llivirnn @rares Patented May 12, 1903.

PATENT OFFICE.

VWILLIAlVI II. COLE, OF VATERTOWN, MASSACHSETTS, ASSIGNOR OF ONE- LAM P.SOCKET.

SPECIFICATON forming part of Letters Patent No. 727,590, dated May 12, 1903.; pplicatimi tiled August 19, 1902. Serial No. 120.183. (No model.)

To @ZZ whom, it mfr/y concern:

Be it known that I, WILLIAM H. COLE, ot Watertown, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Lamp-Sockets, of which the following is a specification.

This invention relates to sockets for electric incandescent lamps; and-it hasY for one of its objects to improvethe contact between the terminals of the lamp and the'electrodes of the socket. v

The invention also relates lmore particularly to series sockets for street-lighting having a switch adapted to preserve the continuity of the circuit through the socket when the lamp is out of the socket, said switch being opened by the insertion of. the lamp. The invention improves this style of socket by affording better protection to the switch from the effects of dust, &c.,`aud also securing better contact between the switch-points by preventing the passage of current through the spring or springs employed to close the switch, which tends to anneal and weaken said spring, and, finally, the invention incidentally improves the socket by providing a stronger and more durable construction than heretofore.

Of the accompanying drawings, Figure 1 represents a vertical sectional view of a lampsocket constructed in accordance with my invention, said view showing a lamp in the socket. Figf2'represents a section at right angles to Fig. 1 without the lamp. Fig. 3 represents a plan view of -the socket. Fig. 4 represents a vertical sectional View showing a modification. Fig. 5 represents a section at right angles to Fig.`4.

The same reference characters indicate the same parts in all the figures.

In the drawings, is an insulating-base, of porcelain or other suitable material, formed with a hollow hood 11 at the bottom of which is located a semiannular fixed electrode 12, having a projecting stem 13, provided with a binding-screw 14. ln the Jform shown in Figs. 1, 2, and 3 this electrode is secured by screws 15 15, passing through holes in a middle insulating-partition 16 of the base to a metallic plate 17, overlapping the edges of a chamber or recess 1S, formed in the lower part of the base. 19 is the other electrode of the socket,

. the socket, as represented in Fig. 2, the plate lbetween the switch members-17 23 after the having a binding-screw 20 at its outer end and provided with an axial projecting screwthreaded post 21, into which is screwed a stem 22, passing through a central hole in the partition 16, and having a head 23 at its lower end normally held -by a spring 24 in contact with the plate 17.

It is apparent that when the lamp is out of 17 and head 23 are held in contact by the spring 24 andconstitute members of a switch which preserves the continuit-y ofthe line-circuit from the electrode 12 to the electrode 19.

25 represents the lamp, the ends of whose filament are connected to a middle terminal 26, internally threadedv to engage the post 21, and an annular terminal 27, adapted to make contact with the electrode 12. When the lamp is inserted inthe socket, it is screwed into engagement with the post 21, and its terminal 27 comes in contact with the electrode 12. Said electrode 12 constitutes an abutment resisting further inward movement of the lamp, and the further rotation of the lamp therefore draws outwardly the post 21 and the remainder of theelectrode 19, with its stem22 and head 23,against the tension of the spring 24, thereby breaking the contact circuit has been completedthrough the filapositioned in the socket, its terminal 2 7Vis held in contact with the electrode 12 yieldingly with ability to rock to a limited extent in all directions. The lamp is thus enabled t0 seat itself and secure an effective contact between the members ,12.27, even when dirt or grit resides between certain portions of said members, as is apt to be the case when the lamp is placed in Yan exposed situation, such as a street. The spring 2 4 is of course made sufficiently strong to insure that the contact shall be wellmaintained. When thela'mp is out of the socket and the switch members 17 23 are in contact, the head'` 23 is likewise enabled to seat itself with a universal movement, and thus insure a good contact. It is also one of the features of my invention to have the electrodes 12 19 separated from the switch members 17 23 by partition 1G, so that Said switch members are protected from the entrance of dust and other foreign matter to a greater degree than formerly.

. The protection of the switch members 17 23 is increased by forming the chamber or recess 28 in the bottom of the porcelain base 10 and`covering said chamber with a plate 29.

Figs. 4 and 5 show the adaptation of my invention to the type of lamp having an externally-threaded neck or terminal. This requires an internally-threaded electrode 30, such as is shown in Figs. 4 and 5. The electrode 30 is connected by screws 31 31, passing through holes in the partition 16, with a plate 32, located in the chamber 18 and projected downwardly by springs 33 33, surrounding the screws 31.

34 is a xed central electrode having a stem 35 passing through a central hole in the partition 16 and -engaged with a nut 36, whose head constitutes a switch member complemental to the plate 32 for preserving the continuity of the circuit when the lamp is removed.

It will be noted that the spring or springs in both forms of my invention are electrically independent of the switchthat is to say, the spring is so arranged as not to be traversed by the current, either directly or in parallel with some other conductor, whether the switch be open or closed, and there is therefore no annealing and deterioration of the spring such as is observed where the spring forms one of the switch points or members.

I claiml. In a lamp-socket, a movable electrode screw-threaded to engage a threaded terminal of a lamp, a second electrode adapted to engage the other terminal of the lamp, and a switch adapted to close the circuit between said electrodes and operated by movement of said threaded electrode.

2. In a lamp-socket, a movable electrode screw-threaded to engage a threaded terminal of a lamp, a second electrode adapted to engage the other terminal of the lamp, a switch adapted to close the circuit between said electrodes and operated by movement of said threaded electrode, and resilient means eX- cluded from the switch-circuit,for closing said switch.

3. In a lamp-socket, a movable electrode having means for interlocking with one terminal of a lamp, a second electrode, resilient means exerting pressure on said movable electrode in a direction to hold the other terminal of the lamp yieldingly in contact with said second electrode, and a switch for connecting said electrodes, operated by movement of said movable electrode.

4. In a lamp-socket, a screw-threaded -movable electrode, an abutment electrode arranged to resistin ward movement of the lamp, resilient means resisting outward movement of said threaded electrode, and a switch for connecting said electrodes, operated by movement of said movable electrode.

5. In a lamp-socket, a base formed with an insulating partition, a pair of electrodes located on one side of said partition and relatively movable by insertion of the lamp, a switch located on the opposite side of said partition, and electrical and mechanical connections extending through said partition from the respective electrodes to the respective `switch members for normally electrically connecting the said elements and for transmitting the relative movement of the electrodes to the switch t0 operate the latter.

In testimony whereof I have axed my signature in presence of two witnesses.

WILLIAM H. COLE.

Witnesses:

ADELINE C. RATIGAW, R. BULLocK. 

